[pchalamet]

Changes

• Move the FScript CLI, language server, and generated .NET and C# output to .NET 11. Use SDK 11.0.100 for the Docker build and release workflows.
• Keep the embeddable libraries and JavaScript target on .NET Standard 2.1. Pin FSharp.Core 10.1.404 to match existing extension providers.
• Update System.Text.Json and Tomlyn.

Validation

• make build TB_FLAGS=--retry, make test, and make smoke-tests passed.
• make fable-test passed all 152 tests with only the .NET 11 runtime installed.
• The upgraded CLI loaded Terrabuild's .NET 11 extension provider.